1. Technical Field
Example embodiments relate to polymers for an anti-reflective coating, compositions for an anti-reflective coating and to methods of forming a pattern of a semiconductor device. More particularly, example embodiments relate to polymers for an anti-reflective coating that may be developed by a developing solution, compositions for an anti-reflective coating and to methods of forming a pattern of a semiconductor device.
2. Description of the Related Art
As semiconductor devices having high operational speeds and large capacitances are in high demand, semiconductor manufacturing processes have been developed to improve the integration degrees, reliability and/or response speeds of semiconductor devices. Various methods for forming a fine pattern (e.g., a photolithography process) have been developed to enhance the integration degree of the semiconductor devices.
For example, with a photolithography process, a photoresist pattern may be formed using a photoresist composition. Generally, the photoresist composition may have solubility in a developing solution, which may be significantly different before and after exposure to light. Therefore, a photoresist pattern may be formed by a coating process using the photoresist composition, an exposing process and a developing process. A photoresist film may often be formed on a substrate on which a highly reflective layer and/or a structure having a stepped portion or an irregular surface may be formed. In such a case, light passing through the photoresist film may be readily reflected again toward the photoresist film by the underlying layer or structure. The reflected light to the photoresist film may cause reflective notching, standing wave effect and/or non-uniformity in a dimension of a photoresist pattern. Accordingly, an anti-reflective coating layer, which may absorb light in a wavelength range used as a light source in the exposure process, has been developed to suppress such reflection of light toward the photoresist film.
The anti-reflective coating layer may be classified into either an inorganic anti-reflective coating layer or an organic anti-reflective coating layer. The inorganic anti-reflective coating layer may be formed by a deposition process, e.g., a chemical vapor deposition (CVD) process. The organic anti-reflective coating layer may be generally formed by a spin coating process.
The organic anti-reflective coating layer may be conventionally patterned by a dry etching process. However, a loss of thickness of a photoresist pattern may occur while the organic anti-reflective coating layer is patterned by the dry etching process. To provide a sufficient thickness for the photoresist pattern, a method of increasing the thickness of the photoresist film has been suggested. As the resolution of a photoresist pattern significantly increases, an additional reduction in the thickness of the photoresist pattern may be required. Methods for overcoming difficulties associated with photoresist loss and also producing a pattern having an improved profile or fineness are still needed in the art.